Height computing apparatus



HE IGHT COMPUTING APPARATUS.

Fil'ed June 2a, 1943 s Sheets-Sheet 1 FigJ.

Inventor": George W. Fyler,

b MQ/W His Attorney.

M 6, 1948. G. w. FYLER 2,444,770

I HEIGHT COMPUTING APPARATUS Filed June 28, 1943 3 Sheets-Sheet 2 Alva.5 //v 056/7555 Invent or: George W. F'yler;

July fi, 18. s, w, FYLER 2,444,770

HEIGHT COMPUTING APPARATUS Filed Jime 28, 1943 3 Sheets-Sheet 3 Rs/ne 6Inventor: George W Pyler;

b W MMZ H is Attorney Patented July 6, 1948 HEIGHT COMPUTING APPARATUSGeorge-W. Fyler; Stratford; Conn.,- assignor" to General Electric 3 CompNewYork any; a corporation of Application'June28';1943, Serial No.492;199

11 Claims (Cl. 235-61) Mv i'nvention relates to apparatus forcomputing-values involving the sines of angles and par ticularly to suchapparatus for use in connection a with rangefindi'ng devices tocalculate-and 'indi catedirectly the height ofa distant obj=ect'.- 5

Radio-apparatus for finding the directiomand :1 range of I distant objects-'- commonlyincluds de-= vices indicating the range and angle" ofelevation i from which the altitude of' th'e-di stant object may be'computed. Various-computin'gd'evices have been employed *in connectionwith radio locators to -indicate 'the l'al-tit'ude of='the locatedobjects Mechanical computers for" this --processare generallycomplicated and expensive: and it is de'sirable to provide a simple andrugged form oflap paratus whichvvill secure "adirect readingfwithin apredetermined degreeof accuracyl Electrical computing apparatus forproviding values dependent uponasinefunotion hasge'nerally re quired' anelectrical circuit -component having-7x a characteristic varyinginaccordance with the sihefunctiOn. These'sine varying components areobviously somewhat complicated-to construct: Accordingly; it is anobject/ oi my invention' to provide an improvedelectricalapp'aratusforconrputing -th'e altitude of a distant objectdependent-s upon range-andangle of elevation andwhicliim oludes linearelectrical circuit components It is another object of myinvention to provide an im-proved apparatus'forcomputing the+ height" of distant objectswhich employs alter nating current transformers having substantiallylinearcharacteristics A'n'other' object of invention is w provide w acomputing devicesui-tablefor calculating the 1 :alt'itudaof distantobjects 1 and which includes linear-electrical circuit componentsarrangewto provide a" sum" of 'voltages approximatingthe i powerseries-'for a=sirie function.

The features of my inventionwhich I believe to'be novel are set'forthwith-particularity in the appended*claims. My invention itself;however,- both as" to its organizationand method of=operation togetherwith-"further objects-and advantag-es thereof mayhest-be understood'b y'reference; tdthfifollotving description taken" in -connection' with "theaccompanying drawings in which Figs."

1, 2 and? represent; diiferen't embodiments of :m invention employedwith radio locating apparatusr-Figsc l and 5 represent-curves o-rgraphsfor analy'zingthe operating characteristics-of the de-' viceembodying my invention; and' 'Figi d'represents'still' anotherembbdimentw' Briefly: one form "ofmy invention as illustrated inthedrawings comp'rises'two autotransformers connected across a'constan'tvoltage sourceof al ternating current? The secondary circuit of' oneoftlie transformers is" varied in accordance with the sine of the angleof elevatiomofthe dist-ant objE'ctas determmedbra'radidlocator and thesecondary circuit of: the other transformer -is'- varied in accordancewith the range of 1 the :di-s' I tant oloject as determinedby thelocator. I this manner: secondam voltages are provided which areproportional-W0 the sine of I the anglei of elevation and to the arange: An -'electri'cal strument is-iconnectedto the secondarycircuitsof the transformers in sucli'aimanneraas to pro vi'de a readingproportional to: theproductof their sine of the angle and" the rangew-Thisf-meter -w may then be calibratedxin termsof the height-of theobjectt In another form 1 ofmy-iinvention a: plurality ofautotransformers are connected rin' cascade across a constantvoltagesource of alter-= nating current The secondary" voltage of the firsttransformer is variedvirr accordance:With the range of the distantobject, and the rsecondarm' voltages of a pluralitya -0f1 the. remainingtrans-i formers are varied directly in accordance-with: the anglesvofelevation 0f 1 the obj ecta These! late A ter-z transformers connectectin "cascade?provider: onei voltage proportiona-h to the lproduct: of theangle by the range and: another voltage proper-'2 tional to the productof: thethird:,power: of the??? angle by 'therrange. From the' first of:thesew: voltagesis-subtracted?a predetermined: portion of i r the secondvoltage." This .zportionvis selectedwso that thecombinedivoltages--approximate? the-1: power series for the: sine: a filnction so":-that1:a.ovoltage is available which is proportional to thewproduct of the-range; and the sine 0f-the'.:angle'r.' of' elevation."Ant indicatinginstrument resporr-er' sive to thistevoltagermayflthen-becalibrated o": indicatesdirectly the altitudezv-h'of the objectzu A12:correctionwfor the additional altitudesduei tO'the-i' curvature of atheearthlmay be introduced'in'theiw meter: circuit :to. provide: a morecorrect indication of the altitudesof'objects' at greater-distancesReferring now to the drawing, the range findings" "and height computingapparatus-shown in Figs-1 comprises a radiov locator Ill including adipolem antenna I I associated With 'a parabolic reflector: IZ-pivotally mounted onzai pedestal I 3. 1 Thei'lol cator H1 isprovidedwith a cathode raytuloerorw electron discharge device vl 4 fhavingia vfluorescent screen on which light traces appear indicating?objects in the path toward Which-Lthe. reflector: l2 -is directed. Anoperating and indicating arm: I5 is either manually or automaticallypositioned: in accordance with the range of the distantobjectuas-indicatedby the light traces on thescreenw of the-cathode raytube. When the reflector. I2 is pointed directly at a distant object'theangle of elevation of' the objectis indicatedhy the angle between thecentral axis of the reflector" and the horizontal. High frequencypulsesre flected 'fr'om or transmitted by distant objects and impressed on theantenna l l produce corresponm ing pulses or peaks on the' light trace'of :tlie

cathode'ray tube asindicated atlfig H and l 8:, c

for example. By moving the range arm l an aperture pulse 23, whichappears as a ditch in the light trace, is moved along the line of thelight trace on the screen of the tube l4. When the aperture pulse iscentered with respect to one of the pulses l3, l1 and I8, the armindicates the range of the distant object from which that pulse has beenreceived. In the drawing, the pulse 18 has been indicated as centeredwith respect to the aperture pulse 23. The scale for the pointer 15 maybe calibrated to indicate directly in miles the range of the distantobject.

The height of a distant object, neglecting the curvature of the earth,is equal to the product of its range and the sine of its angle ofelevation. The term range as employed in this specification designatesthe line of sight distance to the object which is sometimes called theslant range. For great distances, it may be necessary to include thecorrection required because of the curvature of the earth; thiscorrection which varies with the second power of the range is added tothe altitude of the object as determined by the product of the range andsine of the angle of elevation. In order altitude of the distance objectand to provide a direct reading which is available simultaneously withthe readings of the range and angl of elevation, I provide a calculatingdevice 22. The device 22 includes two autotransformers 24 constitutingvoltage dividers and connected in parallel across a suitable constantvoltage source of alternating current indicated at 25. Transformers 23and 24 are provided with variable secondary circuits, the number ondarycircuits being determined by the position of the contact arms 23 and 21,respectively. The contact arm 26 is moved by means of a rack 28 andpinion 29 through a Scotch yoke connection 30 having its crank rotatedin accordance with the angle of elevation as determined by the refiectorl2 through a 5 table connection 3| indicated by a dotted line, Thecharacteristic of the Scotch yoke connection is that when the rotatingmember including the crank is moved through a predetermined angle thereciprocating member, that is, the rack 28 of the drawing, is moved inaccordance with the since of the angle. This mechanism is, therefore, amechanical means for converting angular movement to simple harmonicmotion or sinusoidal movement. The secondary voltage of the transformer23 is, therefore, varied in accordance with the sine of the angle ofelevation. The secondary voltage of the transformer 24 is varied inaccordance with the range of the distant object, the contact arm 21being connected to the operating arm I5 of the device l0 through asuitable mechanism 32 as indicated by a dotted line. In order to obtainan indication proportional to the product of the secondary voltages ofthe two transformers an electrical instrument 33 is provided. Thisinstrument is of the electrodynamometer type and includes two separatecoils 34 and 35, one of the coils being stationary and the othermovable. Instruments of this type are constructed and arranged so thatthe relative movement between the coils provides an indication of theproduct of the electrical quantities energizing the respective coils.The coils 34 and 35 have been indicated as connected across thesecondaries of the transformers 23 and 24, respectively. Since theindication of the instrument 33 is proportional to the product of therange by the sine 0f the angle of elevation, thescale of the instrumentmay be calibrated in to compute the height or i 23 and 1 of turns in thesec- '1';

. ance with the range of the distant object.

terms of the altitude of the distant object. For example, it may becalibrated to indicate the altitude of the object directly in feet.

During the operation of the range and altitude finding apparatus shownin Fig. 1, the reflector I2 is moved in the desired direction until amaximum signal is received from a desired object as indicated by thecorresponding pulse appearing on the screen of the cathode ray tube l4;obviously, auxiliary apparatus (not shown) is normally employed tofacilitate precise pointing of the antenna. The angular position of thereflector l2 then indicates the angle of elevation of the object and thearm 26 of the transformer 23 is moved by the rack 28 to a positionproviding a secondary voltage corresponding to the sine of the angle ofelevation. The operating arm l5 of the locator I0 is then moved untilthe aperture pulse 20 is centered about the pulse representing theobject in question and the pointer [5 then indicates the range of theobject in miles. At the same time the secondary voltages of thetransformers 23 and 24 are impressed on the coils 34 and 35 of theinstrument 33 and the instrument indicates directly the height of theselected distant object. When the apparatus I0 is operated to followautomaticall the changes in position of the distant object, theinstrument 33 provides a continuous indication of the altitud of theobject.

The apparatus illustrated in Fig. 2 is similar to that shown in Fig. 1.However, a different arrangement for connecting the indicatinginstrument to the transformers is employed; corresponding parts havebeen designated by the same numerals. In the apparatus of Fig. 2 anautotransformer 31 is connected across the constant voltage alternatingcurrent supply 25 and is provided with a rotatable contact arm 38 whichis operated in accordance with the range, it being connected to therange determining arm 15 through the coupling means 32. The position ofthe arm 38 thus determines the transformation ratio of the transformer31 directl in accord- A second transformer 39 is connected across thesecondary circuit of the transformer 31 so that the two transformers arein cascade and a voltage proportional to the range of the object isimpressed on the primary winding of the transformer 39. The transformer39 is provided with a contact arm 40 which with the sine of the angle ofelevation by operation of the rack 28 and Scotch yoke mechanism 30.Since the sine of is equal to 1 and the sines of all other angles areless than 1, the full voltage of the transformer 39 may be made torepresent unity and the fractional portions of the transformer windingincluded in the secondary circuit thus represent the sines of anglesless than 90, and since the voltage across the winding 33 isproportional to range, the fractional voltage across the secondary ofthe transformer 33 is proportional to the product of the range and thesine of the angle of elevation. In order to provide a direct indicationof the altitud of the distant object a suitable indicating instru mentsuch as a voltmeter, may be connected across the secondary of thetransformer 39. This instrument may be calibrated directly in feet ofaltitude. The device of Fig. 2 thus provides a direct indication of thealtitude of the distant object which is available simultaneously withthe indication of range and angle of elevation.

In Fig. 3 I have illustrated a range finding is moved in accordancedevice k including =a=1ca1culating apparatus PWhiCh =employs )linearelectric circuit components and eliminates the necessit of employingtamechanical converting arrangement for .obtaining "voltsages proportionalto'the'sines orangles. The rangezisand anglefinding "apparatus of Fig-.3" are similarto. that ofiFig. "laand corresponding'parts ihavebeen'designated. by .the same numerals. In terrier tol =providea-1directrreading of the altitude #01; the' distant object, a":computingapparatus-'42 is provided which includes =-acdirectrea;ding orindicating instrument 43.

The calculating apparatus 42 has been illustrated as including fourautotransformers 35, 46, WT and 48, respectively, connected in cascade"across the constant voltage I alternating current supply 25. Thetransformer lfi is connected directly across the source and its variablesecondary circuit is controlled by a contact arm 49 rotated by thecoupling device 32 directly in acrcordancewwith the range -as-determinedby the arm I5. The autotrans-formers 46,411-and; 4B are z provided withmovable contact arms 50,- -5I and @51 respectively, whic'hare ganged, ormechanically coupled, to rotate togetheruand are driven directly by theooupling 3 lsothattheirpositions rare directly dependent upon theangleof eleva r tion. Thetransformersdfi, -41 and-48 are convonected'so thatthey: provide voltages which correspond' to termsof the power seriesiorthe sine functionzand -which: may be added toprovide a"voltage-proportional to the sineof the: angle of elevation.Furthermore,v since this voltage isalso iproportional to therange' asdetermined by the operation of the transformer 45, the final voltage isproportional to the product of theirange'and the. sine of theangle'ofelevation.

The power-series for determining the sine function-of anangle'when theangletisexpressed in radians isgivenby the following equation:

'In Fig.4 areplotted curves representing the vsi'nemf an: angle andtheifirst three terms of." the above series for anglessfrom' o to 90 orradians. From these curves it is evident that the sine curve maybeapproximated by subtracting from the straight line representing theangle in radians the value of the cubic curve and lay-adding 'the valueof the fifth power curve all fora given value of the angle. The firsttwo terms or the power ser-ies provide a reasonably-good approximationfor-the sines'of angles up to about-60. "In order to providewoltageswhich can be addedto approximate the value of the sine of the angle ofelevation the transformers, M-and 'QBare connected so that thetransformer' fi provides a sec- "ondary voltage proportional to theangle of elevation, the transformer 41 provides-a secondary -voltage:proportional to the square of the angle ofielevationland thetran'siormer-'l8- provides a z'secondaryvoltage proportional to the'cube'of the "angle" of elevation. Since the voltage impressed on thetransformer 46-is=proportional to the range as determined'by theposition of the contact arm 49 of the transformer? 45,? the secondaryvoltages "of the" several transformers 46, and QR-are thereforeproportional to the product of the range :iand the first; secondandthirdpower;respectively, of. atheaangle rofvelevation; .=The' indicatinginstrurimenti 4Msconnectedrbbtween the contactlarm fill 16 and 1 acontactiarmzr53r=of pansautotransformer '54, -the:*primary of which'is;connected acrossthe outtputxofithe transformer-48. ItwilLbe evident thatthe instrument 43 is responsive; to :a voltage equal r5 tothedifiereneebetween the secondarywvoltage of the" transformer mil-and thesecondary voltage ofithe transformers. The primary volta-getof =thetransformerv 54=is proportional to the product 101? therangevandthethirdpowerof the angle of 3-10 elevation, and s the :secondary voltage is: afixed 1, proportion .of the primary voltage which is soelectedto;providetthe,correct value for the second -term'of. the powereseries andalso a correction for -the-2omission ofzall=thezterms of the seriesabove the third power? term. -I have found'that'by -subv.stituting thevalueiof 6.1 for 3! or 6.0 in the power series, values v of the-sine of:an angle'of elevation -which-are-accurate within one per cent of errorup to anangle of elevation of 70 may be obtained. Thersecondaryrof thetransformer fi is,'therefore, made toprovide a-voltage equal to (1:25of: the primary-voltage. In order. that! the apparatus may be employed:'for obtaining altitude whenthe.angleofeleVation is either greaten thanor less. than-one radian; the input voltages of: the transformers 46,r41 'andi48 are impressed across -a portion "'of the primaryWinding'representing cone radian, the:arms:50,i-5 kand-52 swinging abovetthesepoi-ntswvhen thezangle of elevation isgreater than one radian. The:transformers. therefore, voperateias 'step-up-wor: step-downtransformers, it '35 being :obvious that whenzthe'contact arms 50,-5I

. -a'nd :52 are-directly opposite the primary connection representingonegradian then the first; second and rthirdapowers-of theangle are all'equal to unity. The instrument fl may then be calibrated -4O With thevalue of voltage:at one radian'considered as unity and. voltages belowasfractional values. -The circuit ofFig53 provides-asimple andeffectivecomputer whichincludes only linearly =varyling circuit componentsand-avoids the necessity 15 .of providing mechanical means forconverting i the rotation: pmpontional to theangle to rotationproportional Y to: the sineoof' the angle.

"Under-some conditions of' operation and'i particularly when the:rangeffinding apparatus is employed formeasuringet-he ranges of objectsat :great distances, awcorrection to account for the earth s curvaturemust beiadded to the calculated altitude to obtain thetruealtitude.The'diagram ..oi-Fig. 5 .illustratestthe geometry 'by which-the 55altitude' of: the distant :object. is. determined. :In

Fig. 5 a distant object such as an airplaneisindicated at 56, at anangle of elevation indicated at 0 and at a distance from-the rangefinding apparatus indicated as R, the calculated altitude ofthe-planeris Risine aas indicated. The true height 'is ofcoursewmeasured along :aperpendicular H "1from cairplane 561 130? the"earths surface and. the sadded 'altitudeito correct for the curvature ofthe earth is the difference *betweent Hand" R sine 0,

indicated-asHc. When the rangeR'is determined rin-nautieal milesthealtitude in feet may be'found a by the efollowingrequationz Height inieet=6000R sine 6+.865 R '70-" 0 being the 'valueof th radians.

"The computing apparatus shown in F1 vides" an earth curvature r-paratusisoperated-by a'ra finding: devicesimilarto e true-"angle of elevationin g. 6- procorrection; This apdiodirection and range 'puter shown inFig. 6 comprises a arms 64, 65, respectively, coupled to be rotatedangle is .98, approximately,

2 and 3 and corresponding parts have been designated by the samenumerals. The height complurality of autotransformers 58, 59, 66, 6|, 62and 63. The transformers 58, 59 are provided with contact which aremechanically simultaneously in accordance with the range throughoperation of the coupling device 32. The remaining transformers '60, 6I, 62 and 63 are the sine function components and are provided withcontact arms 66, 61, 68

and 69, respectively, which are ganged together so that they are movedsimultaneously in accordance with the angle of elevation, the arms beingrotated by the coupling device 3| in accordance wtih the angle ofelevation as determined by the antenna H. The transformer 58 is similarto the transformer 45 of Fig. 3 and is connected across the constantvoltage alternating current source 25 in the same manner. Thetransformers 60, 6| are connected together in series so that theyprovide in effect, a single transformer having double the number ofturns and, since the arms 66 and 61 both vary in accordance with theangle of elevation, the effective secondary circuit of the transformers66 and 6| in series varies with respect to the entire primary circuit inproportion to the angle of elevation. The two transformers in seriesprovide an output voltage more accurately proportional to the angle ofelevation than if only one transformer were used. The transformers 66and 6| in series are connected in cascade with the output of thetransformer 58 and the transformers 62 and 63 are connected in cascadewith the common series output of the transformers 66 and BI. These fourtransformers operate in a manner similar to the three transformers 46,ll and 48 of Fig. 3 to provide voltages proportional to the product ofthe range and the first, second and third powers, respectively. of theangle of elevation. The arrangement of the sine function transformers60, 6|, 62 and 63 differs from that of the transformers 46, 41 and 4B inFig. 3 in that the entire primary winding of each of the transformers isconnected across the outi put of the preceding transformer and the usedportion of the output voltage of transformer 63 is different from thatof the transformer 48 for reasons which will be pointed out below. Theoutput of the transformer 63 is connected in the primary circuit of anautotransformer Ill having a tap H for providing the desired proportionof the output voltage representing the product of the range by the thirdpower of the angle. The ratio of primary to secondary turns of thetransformer I is only when the unity voltage corresponds to an respondsto an angle greater than one radian,

then a ratio of the transformer H3 must be selected which takes intoaccount this difference between the position of the control arms forunity voltage and their position for unity angle or one radian.

For purposes of illustration let it be assumed that the maximum angle ofelevation is 79, that is, 1.38 radians, approximately. The sine of thisas shown in Fig. 4.

Now if the voltage corresponding to an angle of 1.38 radians at the fullor maximum rotation of the contact arm is considered as unity, then thevoltage corresponding to the sine of the angle must be equal to .98divided by 1.38 or .71 times the unity or full rotation voltage. Thedifference between the sine voltage and the unity is, therefore, .29times the unity voltage, which is equal to unity voltage divided by3.45. At full rotation the secondary voltage of the transformer 63 isunity voltage; therefore,

is the desired factor and the transformer 10 is arranged with its outputtap H connected to provide a voltage which is l times the output voltageof the transformer 63. This ratio then provides a satisfactoryapproximation of the second term of the power series for all angles upto 79 when the full rotation of the control arm corresponds to 79.

The difference between the voltage of the output of the transformers 60and 6| in series and the output voltage of the transformer 16 provides avoltage which is approximately proportional to the product of the rangeand the sine of the angle of elevation for all angles up to 79 and anindicating instrument [3 having a moving coil 11 connected to beresponsive to this voltage may be calibrated in terms of the height of adistant object.

In order to provide a more accurate indication of the altitude ofobjects at great distances from the range finding apparatus the outputof the transformer 59 is connected across the primary of a transformer15. Since the transformer 59 is in cascade with the transformer 56, itsoutput voltage is proportional to the square of the range. The secondaryof the transformer 15 is designed to provide a small fraction of thevoltage at the secondary of the transformer 59. The secondary of thetransformer 15 is connected across an adjustable potentiometer 16 in thecircuit of the instrument 13 so that the required voltage is introducedin the circuit of the instrument which voltage is proportional ot theearths curvature correction required at any particular range. Thepotentiometer 16 is connected in the circuit of the moving coil 1'! ofinstrument 13 so that the voltage across the selected portion of thepotentiometer is added to the voltage across the output of thetransformers 60 and 6| in series. The instrument 13 has been indicatedas of the wattmeter type which includes the moving coil 11 and astationary coil 12, the coil 11 being connected in the circuit justdescribed and the other coil 12 being connected directly across theconstant voltage source 25 through a condenser 18. This connectionprovides an alternating current voltmeter having a substantially linearscale. A resistance 19 is provided in series with the coil 11 in orderto calibrate the meter in accordance with the voltage of the source 25.A fuse or other suitable overcurrent protective device 8|] may beprovided in the circuit of the meter to protect the meter againstoverloads which might be caused, for example, by simultaneous adjustmentfor maximum range and maximum angle of elevation.

During the operation of the apparatus shown in Fig. 6 the meter 13 maybe calibrated to indicate the altitude of a distant object directly infeet and simultaneously with the-indication tof -range terms1of-thepower series for the sine of-the angle by 1 the pointer Hi ,and "thetangle of elevation by I ofeelevation, and means .formultiplyinglsaidaplur:thexsettingsofthereflectorlfZ. The-transformersrality of voltages .by-said range voltageanddor t59qandi provide a'correction for change in addingwthe product voltagesto providetavolta'ge measured altitude due :to the curvature of the proportional-.to the productof the rangeandthe :earth .cand the apparatus is;:therefore,-suitable s neoft e a gleof elevationfor the computing Ofathealtitude ofnobjects at 4 lna-systemiforldeterminingthe altitude of a'tgreat-distances:fromthe range finding apparatus. zdis'tant object, thecombination of one-member gll'romathe foregoingitds readilyapparentthatunOVable imaccordance with therange of'the ob- Ihave providedapparatusfor.computingthe alti-u. ,=10= iject and another member movablein accordance ntude of distant objects by electrical means and:withrtheangleof elevation of'the objectpmeans which requires onlylinear-:electric lcireuitw-comdependentmpon the positionof said onemember ponents. Thisapparatus isofrugged-roomtruc- '0 z-provlding avoltage corresponding torthe 1 vtionand is simple sand efiective int-oeration. It --r ne of :the o je t; m n p n n p n h "provides a directreading of altitude which is position .ofiusaid other member for ip oViavailable simultaneously with the reading:- of -voltaeeproportionahto'the -sine of thean fl arangetand ang1e of-elevationtandxwh'ich is 'accuelevation oithe Obj means for combiningsaidcrate-within a predetermined desired degree. voltages to p aproportional to the Although I have showmparticular embodiments p duotcf the-range and the sine of thea of my invention in connection withradio udirec f' l va o r-means for adding to said Eproductiition-andrange'finding apparatus, other modifica- ":voltage acorrection to account for-the curvature tions will readily occur tothose skilled zin'lthe :oi the .earthwwherebythe corrected product volt-:art. It wi1l,-therefore, be understoodxthat I do age i su n i lly potional o'the' vertica1 inotwishimy invention tobe limited to theparelevation of Ltheobject above the surface of the .itieulararrangements shownand described, and I,; earth, means p s ve to thecorrected I i t d. by thesappended 'claimsfto covergllimom :productvoltage for indicatingdirectly ltheu:altiificationstwhich fall: Withinthe spirit and scope o t d s ant jectof my invention. 7 5.-In:asystemfor determining :thewaltitudemf What I claim as new and desire tosecureby atdistantrobjectgtheicombinationof one-.member Letters Patentof the'United'States i movableinaccordance with the range COf thHOb- 1 Ia t m fol determining th altit d of jeot and another member movable.imaccordance =atdistant object, the combination of one member with theangle of elevation of theobjectgmeans movable in accordancewith therange of :the -dependent=upon thepositionofsaid:one -member object andanother "member movable in accord- --lf0l providing a voltage:corresponding ;toaithe ancewith-the angle of elevation -oftheObJ'ect,.;;35"ran-ge of the: object, .:means responsive toesaid it meansdependent uponv the position of said-one a range voltage and dependentupon Athepos'ition member for producing aquantity corresponding .ofSaid- 061161 "member for producing a' voltage i to the range of theobject, means dependent upon -*-proportionalato the product of :therange andrthe the position of said other 'member for producing-.=sine-.of;the::angle of'elevationzof theiobject, means a plurality ofquantities corresponding-to a plu cio'iresponsiv t saidiran e v lta e,for pro u in a rality of the terms of the a power series :for thevoltage proportional to the square of the range,

sine of the angleof elevation, and-means fo commeansior addinga:-predetermined.fraction of said bining said-quantities to produce a,quantity proilast mentionedtvoltage:to saidproduct voltage to portionalto the product of the rangeand the sine correct it touaccount for-thecurvature iof :the of the angle of elevation. vearth', and meansresponsive to the corrected 2. In .a system for determining the altitudeof p oduot voltage for indicating directly t e altia distant object, thecombination of one mem- W l e ofithe'di's a to jectber movable inaccordance with the range of the 6;.'I n a-ssystemfor determining thealtitude of object and another'member movable in accord- 'a distantobject, the combination of onezmember ance with the angle of elevationof the object; eo'xmovablezin accordance with the range of the' obmeansdependent upon the position of said one iect:and:another member movablein acco'r dance member for producing a quantity corresponding'withthelangle of elevation of the :objectr 'ealn to the range of theobject, means dependent upon *includingfirst andesecond :linear Voltagedividing the position of said other element and utilizing -'welenientstand dependent upon the positioncof cs'aid said quantity forproducing a plurality of quanti- .onetmember :for producing voltagesproportional t ties correspondin respectively .to the product of to therange'of 'the object and to\the secondnpower the [range and each of aplurality of the "terms of 1.- iofrthe:rangaarespectively,meansincluding'a pluthe power series for'the sine of the angle of 9112-arality of linear-voltagedividing elements anddevation, and means foradding said productquanti- 'zpenclent upon the position of said:otherwmember i ties to provide a quantity proportional to the forproducing anplllralityiof voltages correspondproduct of the range andthe sine of the angle of "mgr-respectively to eacho'f aplurality oftheiterms elevation. :of thexpower series for the sine ioftthe angleofiele 3. In a system for determining the altitude of vation; means formultiplyingsaidplurality of a distant 0bject,'. the combination of onemember tvoltages'bysaid. range voltage :and foradding'saicl movable inaccordance with the range of the (ifi iprorluctvoltageslto provide avoltage proportional object and another member movable in accordtoutheproduct ofvthe range-and the sine ofnthe ance with the angle ofelevation of-theobject, mangle-oofzelevation; and means utilizingesaidvoltmeans-including a linear-voltage-dividingvelement age proportionalto the second power of the nange and dependent upon the position of saidone g lfer-adding tosaid range-sine product voltage a member'iorproducing a voltage proportional to-m' rcorrection to account for thecurvatureof the the range of the object, means including a pluuearth.rality of linear voltage dividing elements and 7; An apparatus forcomputing the altitude of dependent upon the position of said othermember :a dista'nt o'b ject comprising a first movable unemfor producinga plurality of voltages -correspond- A ber arranged to be positioned inaccordance with ing respectivelytoeachof asplurality ofth'e the distanceto said object, a second movable a ing 1 a voltage proportional to theproduct of the range current, a plurality of member arranged to bepositioned in accordance with the angle of elevation of said object,means including a variable voltage divider having a linearcharacteristic and associated with sag?" first member for producing avoltage proportional to said distance, means including a plurality ofvariable linear voltage dividers connected in cascade with the output ofsaid first divider and associated with said second member for producinga Voltage proportional to the sine of said angle of elevation, said lastmentioned means including means for Varying the Voltage ratios of saidplurality of dividers simultaneously in proportion to the angle ofelevation of said object whereby one of said plurality of dividersprovides a voltage proportional to the angle of elevation of said objectand another of said plurality of dividers produces a voltageproportional to the third power of the angle of elevation of saidobject, and means including an indicating instrument for connectsaidplurality of voltage dividers to provide and the sine of said angle ofelevation.

8. An apparatus for computing the height of a distant object comprisinga source of alternating transformers having adjustable outputs, one ofsaid transformers being connected across said source and the remainingones of said transformers being connected in cascade with said onetransformer, means for varying the output voltage of said onetransformer in accordance with the range of said object, means forvarying the output voltages of a plurality of said remainingtransformers in accordance with the angle of elevation of said object toproduce voltages proportional to the product of said range 1 and thefirst and third powers respectively of said angle, and means arranged tocombine the two last mentioned voltages for producing a voltageproportional to the product of said range and the sine of said angle.

9. An apparatus for computing the altitude of a distant objectcomprising a constant voltage alternating current source, a plurality oftransformers having adjustable outputs, the first of said transformershaving its input connected across said source, means for varying theoutput Voltage of said first transformer in proportion to the distanceto said object, means connecting three of the remaining ones of saidtransformers across the output of said first transformer in cascade,means for simultaneously varying the outputs of said three transformersin proportion to the angle of elevation of said object whereby theoutputs of said three transformers are proportional respectively to theproduct of the distance to said object and the first, second and thirdpowers respect'vely of said angle, and means including an electricalinstrument connected to be responsive to the difference between theoutput voltage of said transformer proportional to the first power ofsaid angle and a predetermined fraction of the output voltage of saidtransformer proportional to the third power of said angle, saidpredetermined portion being selected so that said instrument isproportional to the product of the distance to said object and the sineof said angle.

10. An apparatus for computing the altitude of i a distant objectcomprising a constant voltage alternating current source, a plurality oftransformers having adjustable outputs, the first of cade with saidfirst transformer, means for varying the output voltage of said firsttransformer in proportion to the distance to said object, means forvarying the output voltages of said second, third and fourthtransformers in proportion to the angle of elevation of said objectwhereby the output voltage of said second transformer is proportional tothe product of said angle and said distance and the output voltage ofsaid fourth transformer is proportional to the product of the cube ofsaid angle and said distance, means connected to the output of saidfourth transformer for providing a voltage proportional to a constantfraction of the output voltage of said fourth transformer, and meansincluding an instrument connected to be responsive to the differencebetween the output voltage of said second transformer and said fractionof said output voltage of said fourth transformer, said constant beingselected so that said difference is proportional to the product of saiddistance and the sine of said angle.

11. An apparatus for computing the height of a distant object comprisinga source of alternating current, a plurality of transformers havingadjustable outputs, one of said transformers being connected across saidsource and the remaining ones of said transformers being connected incascade with-said one transformer, means for varying the output voltageof said one transformer in accordance with the range of said object,means for varying the output voltages of a plurality of said remainingtransformer in accordance with the angle of elevation of said object toproduce voltages proportional to the product of said range and the firstand third powers respectively of said angle, means including anadditional transformer having connected across the output of said onetransformer and having its output adjustable in accordance with saidrange for producing a voltage proportional to the second power of saidrange, and means for adding a predetermined portion of said lastmentioned voltage to said sine product voltage to provide a voltageproportional to the height of said object corrected for the curvature ofthe earth.

GEORGE W. FYLER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,154,252 Kennedy Sept. 21, 19151,542,534 Schneider June 16, 1925 1,942,193 Szilas Jan. 2, 19331,986,986 Swartw-out Jan. 8, 1935 2,080,186 Reymond May 11, 19372,198,371 Wolferz et a1 Apr. 23, 1940 2,212,799 Sperry Aug. 27, 1940FOREIGN PATENTS Number Country Date 136,180 Great Britain Dec, 10, 1918'164,765 Great Britain Oct. 31, 1919 245,034 Great Britain Dec, 31, 1925458,274 Great Britain July 5, 1935 OTHER REFERENCES Trautwine, The CivilEngineers Pocketbook, 20th edition, page.153. (Copy in Div. 33.)

Certificate of Correction Patent No. 2,444,770. July 6, 1948.

GEORGE W. FYLER It is hereby certified that errors appear in the printedspecification of the above numbered patent requiring correction asfollows:

Column 7, line 16, for Wtih read with; column 8, line 50, for ot theread to the; column 10, line 40, claim 5, after the word voltage strikeout the comma;

and that the said Letters Patent should be read with these correctionstherein that the same may conform to the record of the case in thePatent Ofiice.

Signed and sealed this 25th day of January, A. D. 1949.

[MAL] THOMAS F. MURPHY,

Assistant Commissioner of Patents.

Certificate of Correction Patent No. 2,444,770. July 6, 19 48.

GEORGE W. FYLER It is hereby certified that errors appear in the printedspecification of the above numberedxpatent requiring correction asfollows:

---Oo11imn 7,'1ine 16, for wtih read with; column 8, line 50, for ot theread to the; column 10, line 40, claim 5, after the word voltage strikeout the comma;

and that the said Letters Patent should be read with these correctionstherein that the same may conform to the record of the case in thePatent Oflice.

Signed and sealed this 25th day of January, A. D. 1949.

THOMAS E. MURPHY,

Assistant G'ommtssioner of Patents.

